The present invention relates generally to a plumbing apparatus, and particularly to a plumbing apparatus or fitting for use with water, and which is fabricated of frangible plastic material allowing for adhesive connection of plumbing components. More particularly, the present invention relates to a plumbing fitting generally of T-configuration for forming a part of a water circulation or distribution system. The inventive plumbing fitting is particularly useful in a water circulation or distribution system for a swimming pool, hot tub, or spa, for example.
In a spa that is adjacent to a pool, it is conventional to have a wall between and common to both the pool and the spa. This wall is conventionally formed of concrete, in common with the rest of the pool and spa. Such a common shared wall is generally referred to as a “dam wall.” The dam wall of a pool/spa is generally only about six inches (15.24 cm) thick in order to use the generally available size of decorative tile. In such cases, the generally available plumbing fittings make it very difficult or impossible to install bubble jets in the dam wall. In order to allow the installation of bubble jets in the dam wall, some pool/spa installations undesirably use a dam wall that is thicker than six inches. In such cases, the dam wall may be as thick as nine inches (22.86 cm) or even twelve inches (30.48 cm). Such a thick dam wall necessitates an increase in the materials used to construct the pool/spa, and increases the costs of materials and construction.
Also, when bubble jets are installed in the dam wall or in the other walls of a spa or pool, they are necessarily close to the reinforcing bars (i.e., “rebar”) required in these walls to reinforce and prevent cracking of the concrete. Conventionally, each such bubble jet is supplied with air from one manifold pipe embedded in the wall of the spa or pool; and from another manifold pipe also embedded in the wall of the spa or pool wall the bubble jet fitting is supplied with pressurized water to drive a jet of bubbly water. As a result, because of the sizes of the manifold pipes and of the bubble jet fittings, even when these relatively large manifold pipes are spaced adjacent to the reinforcing bars, the walls of the spa or pool must be made thicker than is desired in order to provide sufficient material into which the pipes and fittings can be embedded. Accordingly, the use of construction materials, especially the use of concrete to construct the pool walls, increases as a result of the conventional configuration of plumbing fittings.
Particularly, this increased use of construction materials is the case because that extra thickness of the pool or spa walls which is necessary simply to accommodate the plumbing pipes and fittings is generally carried over to other parts of the pool or spa wall as well. That is, even though many other parts of the spa or pool walls do not include plumbing fittings, they are nevertheless made thicker than would otherwise be necessary. As a result, the undesirably increased wall thickness for the pool wall which occurs because of the embedded plumbing fittings also appears over all or a substantial portion of the pool, greatly increasing the amount of concrete required for pool construction.
Further, during construction of in-ground spas and swimming pools utilizing plastic piping (which is frangible), it is common for a rough excavation in the ground to first be prepared. Then, it is common for the construction personnel to complete and contour the excavation in the earth, install the rebar (usually in a crossing or mesh pattern), install the necessary plumbing fittings by laying these plumbing fittings and connecting pipes into the excavation on or within the mesh of rebar, all preparatory to placing of concrete (i.e., sprayed-in-place concrete) which will form the walls and bottom of the spa or pool. In this context, it is desirable for the plumbing pipes and fittings to lay immediately adjacent to the rebar or adjacent to the earth of the excavation. This is true for at least two reasons. First, such a placement of the plastic piping and fittings economizes on the use of space, which space must be filled with concrete, thus reducing the concrete requirements for construction of the pool or spa. Secondly, during construction, with construction personnel working within the excavation which will become the pool or spa, it is not uncommon for pipe and fittings to be stepped on by construction personnel. Because the pipe and fittings are generally made of PVC plastic, which is frangible (or breakable), such an event of stepping on a pipe or fitting can result in breakage of the pipe or fitting, or both. If the breakage is discovered and repaired before the concrete is placed, only a minor expense and inconvenience results. However, in the event the breakage is not discovered and repaired before the pipe or fitting is encased in concrete, then a very expensive and time-consuming repair may be required.
Still further to the above, and still in the context of in-ground pools and spas which use PVC plastic pipe and fittings (or pipe and fittings made of other plastic materials which can be assembled with adhesive), it is desirable to have the plumbing system drain completely when water is removed from the system. Such is the case in the event, for example, that the pool is drained for winter, or for maintenance. Water which does not drain from the plumbing during winter, for example, may freeze and cause a pipe or fitting to break. Also, even in areas where freezing is not a concern, the water which remains in the plumbing of a drained pool or spa may grow algae, bacterial slim, or fungus, which can then require extra cleaning of the pool when it is to be refilled with water.
As can be seen, there is a need for an improved plumbing T-fitting that may be installed within a comparatively thin dam wall, such as within a six-inch dam wall, as often is desired for a spa, pool, and the like.
Also, there is a need for an improved plumbing T-fitting that may be installed close to the reinforcing bars of a pool or spa wall, or close to the earth within an excavation, so as to allow the pool wall to be constructed thinner and to us less concrete than is required by conventional plumbing fittings of T-configuration.
Further, it is desirable for a plumbing T-fitting to be configured so that the frangible material (i.e., plastic) of the fitting is less likely to be broken by the fitting or pipes connecting to that fitting being stepped upon.